Expanding mandrel



1952 v. E. ENZ 2,615,644

EXPANDING MANDREL Filed Sept. 12, 1950 26 I9 I? IO I2 22 20 l5 a? m I la a I L Laminated Material .J 22

. m Laminated Material WITNESSES: INVENTOR Vern E. Enz. a3

ATTORNE Patented Oct. 28, 1952 I EXPANDING 'MANDREL' Vern-QELEn Jeannette, Pa.,,assignorto Westing: house. Electric Corporation, East. Pittsburgh,... Pa., .a corporation of Pennsylvania. 1

Application September 12,1950, SerialNo. 184,494 (of 242-72) 5. Claims. 1

Thisinvention relates'to-mandrels andparticu- I larly to expanding mandrels.

Expandingmandrels have been employed heretofore in various industries to support Winding cores lor. spools. However, the knownexpanding mandrels were made from a rigid, non-flexible material, :with :the. result that it"has been found to be difficult to expand and contract the mandrel.a The stiffness or non-flexible characteristic of the knownmandrels is a definite limitation on the use of such mandrels since considerable time must be spent in placing the Winding core or spool on themandrel and also in disassembling it from the mandrel..

It is desirable to provide anexpanding mandrel which. is light. and so flexible that it can be readily 1 expanded to securely hold the winding core or spool thereto and easily contracted to permit the rapid removal of the winding spool therefrom.

An object of this invention, is to provide an expanding mandrel havin -a flexible end portion which: can be readily adjusted to facilitate the mounting of. a winding core thereon or the removal of the winding core therefrom.

Another object of this inventionis to provide,in

an expanding mandrel having a flexible end portion, means for; frictionally engaging the flexible end portion to effect predetermined-movement thereof, to control the expansion or contraction of the end portion and to prevent slippage between theengaging means and the flexibleend portion after said predetermined movement is effected.

Other objects of this invention will become apparent from the following description, when taken in conjunction with the accompanying drawing,

in which:

Figure l isa plan view partlyjin section of an expanding mandrel constructed in accordance with this invention; I

Fig. 2 is an endyiew of the apparatus shown in.

Fig. 1; and a Fig. 3 is a View in section taken along the line III-III ofv Fig. 1 of the expanding mandrel constructed in accordance with this invention.

Referringto Fig. f the drawingthere is illustrated.an, expansible mandrel 8 embodying the teachings of .this'invention. As illustrated the mandrel 8 comprises a tube body 10 formed from laminated layersoffibrous material impregnated witha resinous binder and consolidated under heatand, pressure; The fibrous material may be either, duck; clotl,1,-paper, woven glass,,or other similar fibrous; materials. It is; however, preferableto used kraftcpaper as. the1fibrous material. The binder maybe anysuitable syntheticresin,

- 2 v such :as phenoleformaldehyde or hyde..

In order: to. provide an expansible-and ,contractible; mandrel 8, one end of;the tube body l0 is provided with a plurality of. slots l2. In. this embodimentthe slots I! extend lengthwise and they r are substantially evenly spaced; around "the tube body [0. The laminated material between the slots l2'form flexible fingers. 14. The number of slots I! that are cutiisdependent on themateurea-formalderial used for thetube body l0 as well as-thewall thickness and the diameter ofthe tube:

In the embodiment illustrated, where the' tube body! 0 is made fromlaminated sheets of paper impregnated: with phenol-formaldehyde, and: the

tube'body ID. has a wall thickness of of" an inch,.with.the tubewbody 10 6 /3 inches longand having an "outerdiameter of lg-i inchespit has been found that four slots 12 each 2 /ginches long will suffice to. provide sufficient flexibility. to the fingers, M. In other embodiments thenumberz of slot-s 12 may be varied depending on the'size and thickness of the tube' body l0 andzdependin' upon thedegree-of flexibility required.

In order torprovide for controlling-the expansion or contraction of the fingers [4, an expansion member l5; described more'fullyihereinafter, is utilized. For the purpose of supporting thev expansion memberi l5,ia shaft= l6"is provided. .The shaftt'l 6 is provided with threads on both its ends and; is so; assembled; aSifto be non-rotatable with respect 'to'rthe tubebo'dy it; Thus, the shaft I6 is I secured in" assembled relation with respect to the tube body Ill byinsertin'g a 'pin' '11 through the shaft l6 through aligned openings .I8' 'an'd-19 in the shaft I 6" and the tube" wall, respectively; In practice the pinzvl'l is preferably of a length that when. positioned in the-openings'18 and 19; the

ends of'the pin l'l terminate within the confines I of the wall of the tube body H], the pin I! being of a, diameter to give a tight friction fit with the aligned openings!!! and (9. Both the shaft [6 and the pin 11 are preferably made from steel.

The expansion member'or means 15 comprises a wing nut formed of laminated fibrous material impregnated. withv a resinous binder, the components thereof preferably being of the same material as that. of the tube vbody I 6. As illustrated,

the expansion member [5 is provided with a truncated cone section". onflone. end thereof. When the expansion. means! 5 is threaded ontothe shaft IB and turned. thereon in a predetermined directionas'sby applyinga force :tothe wings 2| thereof the truncated cone section 20 frictionally engages the end portion of the fingers I4 so as to apply pressure thereto.

In order to provide an adequate friction engagement between the ends of the fingers l4 and the expansion member IS, the end portions of the fingers l4 and the side wall 22 of the truncated cone section 20 are beveled at complementary angles. In practice, the side wall 22 of the truncated cone section 20, and consequently, the beveled ends of the fingers I4, is provided with a slope which extends at an angle of between 15 and 40 degrees with respect to the horizontal axis of the expansion member Hi. It is necessary to keep within this range in order that the expansion member or means l5 will be held so tightly in frictional engagement against the fingers l4 that it will not turn on the shaft I6 when the mandrel is rotating at a. high speed. As will be appreciated the degree of frictional engagement between the fingers I4 and the side wall 22 depends on the coefficient of friction of the material from which the members I! and 22 are formed, the slope of the side wall 22 and the cooperating beveled ends of the fingers l4, and the dimensions of the tube body l and the slots l2. The most desirable slope within the range given hereinbefore is one that makes an angle of 30 degrees with the horizontal axis of the expansion member I5. In practice the coeflicient of friction of the materials from which the members l4 and 22 are formed is between 1 and 1.5 at break away.

Instead of forming the expansion means l from laminated fibrous material impregnated with a resinous binder as described hereinbefore, the expansion member or means I5 may be molded directly to a given shape or size from impregnated macerated material such as chopped duck or the like as is well known in the art.

In order to prevent a winding spool (not shown) from sliding off of the unexpanded portion of the tube body [0, a plug member 24 is provided for fitting into the unslotted end of the tube body Hi. The plug 24 is preferably provided with a flange 26 at one end thereof, the flange 26 being of a size to be engaged by the winding spool (not shown). The plug member 24 can likewise be made of laminated cloth having a phenolic resin as a binder, or it can be molded from a macerated material. The plug member 24 is also provided with an opening 25 which is aligned with openings I8 and 18 for receiving the pin I! which when in position in the aligned openings l8, l9 and 25, effectively locks the plug in position. I

The expanding mandrel embodying this invention is especially useful for supporting in nonrotating relation, a winding core or spool on which it is desired to wind thread, cloth or paper or any other material.

In operation, when one desires to assemble the winding spool (not shown) on the tube body I II, the expansion member 15 is so positioned that the sloped side wall 22 thereof seats against the beveled ends of the unfiexed fingers H. The winding core or spool is then slipped over the tube body In until it seats against the flange 26. The expansion member or means 15 is then turned in its threaded engagement on the shaft I6 in a direction to cause the truncated cone member 20 to apply pressure to the fingers l4, expanding them outwardly. The expansion means I 5 is turned until the outer surface of the fingers l4 bear tightly against the winding core or spool (not shown) so as to prevent rotation between the members. The expanding mandrel 8 is now in condition for use in winding material on the winding spool. After the winding operation has taken place and one desires to move the winding spool from the tube body [6, the expansion means I5 is turned in the opposite direction until the fingers I become disengaged from the winding spool (not shown) and return to their unfiexed position. Once the fingers 14 have returned to this unfiexed position, the winding spool can be readily removed from the tube body ID.

The expanding mandrel embodying the teachings of this invention has several advantages over the expanding mandrels heretofore used. The expanding mandrel embodying the teachings of this invention can be quickly operated since the fingers [4 thereof can be readily expanded and contracted. Since the mandrel can be easily and quickly operated, it saves both time and labor. In addition, due to its simple construction, its original cost of manufacture is relatively small.

I claim as my invention:

1. A rotatable mandrel comprising, in combination, a tube formed of a plurality of layers of fibrous material impregnated with a resinous binder, the tube having a plurality of slots extending lengthwise from one end, the slotted end of the tube having a beveled end surface, expanding means having a truncated cone member of impregnated fibrous material the slope of whose side wall corresponds to the slope of said beveled end surface, the side wall of the cone being so disposed as to frictionally engage said beveled end surface of the tube to apply pressure thereto, the cone and tube of impregnated fibrous material having a coefficient of friction of between 1.0 and 1.5 at break away whereby the frictional engagement of the cone with the beveled end surface of the tube prevents movement of the cone relative to th tube when the mandrel is rotating, and means disposed to support the expanding means in said frictional engagement with the slotted end of the tube, the expanding means being disposed for movement on the supporting means to vary the pressure applied to the slotted end portion of the tube to control movement thereof.

2. A rotatable mandrel comprising, in combination, a tube formed of a plurality of layers of fibrous material impregnated with a resinous binder, the tube having a plurality of slots extending lengthwise from one end, the slotted end of the tube having an end surface which is beveled at an angle with the horizontal of between 15 and 40 degrees, expanding means having a truncated cone member of impregnated fibrous material the slope of whose side wall corresponds to the slope of said end surface, the side wall of the cone being so disposed as to frictionally engage said beveled end surface of the tube to apply pressure thereto, the cone and tube of impregnated fibrous material having a coefiicient of friction of between 1.0 and 1.5 at break away whereby the frictional engagement of the cone with the beveled end surface of the tube prevents movement of the cone relative to the tube when the mandrel is rotating, and means disposed to support the expanding means in said frictional engagement with the slotted end of the tube, the expanding means being disposed for movement on the supporting means to vary the pressure applied to the slotted end portion or the tube to control movement thereof.

3. A rotatable mandrel comprising, in combination, a tube formed of a plurality of layers of fibrous material impregnated with a resinous binder, the tube having a plurality of slots extending lengthwise from one end, expanding means of impregnated fibrous material disposed to frictionally engage the slotted end portion of the tube to apply pressure thereto, the expanding means and tube of impregnated fibrous material having a coefficient of friction of between 1.0 and 1.5 at break away whereby the frictional engagement of the expanding means with the slotted end portion of the tube prevents movement of the expanding means relative to the tube when the mandrel is rotating, and a shaft non-rotatably disposed with respect to the tube for supporting the expanding means in said frictional engagement with the slotted end of the tube, the expanding means being rotatable on the shaft to vary the pressure applied to the slotted end portion of the tube to control movement thereof.

4. A rotatable mandrel comprising, in combination, a tube formed of a plurality of layers of fibrous material impregnated with a resinous binder, the tube having a plurality of slots extending lengthwise from one end, the slotted end of the tube having an end surface which is beveled, expanding means having a truncated cone member of impregnated fibrous material the slope of whose side wall corresponds to the slope of said end surface, the side wall of the cone being so disposed as to frictionally engage said end surface of the tube to apply pressure thereto, the cone and tube of impregnated fibrous material having a coefficient of friction of between 1.0 and 1.5 at break away whereby the frictional engagement of the cone with the beveled end surface of the tube prevents movement of the cone relative to the tube when the mandrel is rotating, and a shaft non-rotatably disposed with respect to the tube for supporting the expanding means in said frictional engagement with the slotted end of the tube, the shaft having a threaded end portion for receiving the expanding means, the expanding means being disposed to be rotated on the threaded end portion of the shaft to vary the pressure applied to the slotted end portion of the tube to control movement thereof.

5. A rotatable mandrel comprising, in combination, a tube formed of a plurality of layers of fibrous material impregnated with a resinous binder, the tube having a plurality of slots extending lengthwise from one end, the slotted end of the tube having an end surface which is bev eled at an angle with the horizontal of between and 40 degrees, expanding means disposed to engage the beveled end of the tube, the expanding means having a truncated cone member of impregnatedfibrous material having a slope corresponding to the slope of said beveled end sur- 7 face, the cone member being so disposed as to frictionally engage said beveled end surface of the tube to apply pressure thereto, the cone and tube of impregnated fibrous material having a coefficient of friction of between 1.0 and 15 at break away whereby the frictional engagement of the cone with the beveled end surface of the tube prevents movement of the cone relative to the tube when the mandrel is rotating, and a partially threaded shaft disposed in threaded engagement with the expanding means to support the expanding means in said frictional engagement with the slotted end of the tube, the expanding means being rotatable on the threaded portion of the shaft to vary the pressure applied to the slotted end portion of the tube to control movement thereof.

VERN E. ENZ.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 138,947 Smith May 13, 1873 892,287 Morse June 30, 1908 1,281,861 Sibley Oct. 15, 1918 

